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UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
0620/32
Paper 3 (Extended)
May/June 2013
1 hour 15 minutes
Candidates answer on the Question Paper.
No Additional Materials are required.
READ THESE INSTRUCTIONS FIRST
Write your Centre number, candidate number and name on all the work you hand in.
Write in dark blue or black pen.
You may use a pencil for any diagrams, graphs or rough working.
Do not use staples, paper clips, highlighters, glue or correction fluid.
DO NOT WRITE IN ANY BARCODES.
Answer all questions.
Electronic calculators may be used.
A copy of the Periodic Table is printed on page 16.
You may lose marks if you do not show your working or if you do not use appropriate units.
At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question or part question.
This document consists of 14 printed pages and 2 blank pages.
IB13 06_0620_32/2RP
© UCLES 2013
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1
Air is a mixture of gases. The main constituents are the elements oxygen and nitrogen.
(a) (i) Name another element in air.
.............................................................................................................................. [1]
(ii) Give the formula of a compound in unpolluted air.
.............................................................................................................................. [1]
(b) Common pollutants present in air are the oxides of nitrogen and sulfur dioxide.
(i) How are the oxides of nitrogen formed?
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
(ii) How is sulfur dioxide formed?
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
(iii) These oxides are largely responsible for acid rain.
State two harmful effects of acid rain.
....................................................................................................................................
.............................................................................................................................. [2]
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(c) The percentage of oxygen in air can be determined by the following experiment.
large pile of
copper
gas syringe
containing
50 cm3 of air
small pile
of copper
heat
gas syringe
The gas syringe contains 50 cm3 of air. The large pile of copper is heated and the air is
passed from one gas syringe to the other over the hot copper. The large pile of copper
turns black. The gas is allowed to cool and its volume measured.
The small pile of copper is heated and the remaining gas passed over the hot copper.
The copper does not turn black. The final volume of gas left in the apparatus is less
than 50 cm3.
(i) Explain why the copper in the large pile turns black.
....................................................................................................................................
.............................................................................................................................. [2]
(ii) Why must the gas be allowed to cool before its volume is measured?
.............................................................................................................................. [1]
(iii) Explain why the copper in the small pile did not turn black.
.............................................................................................................................. [1]
(iv) What is the approximate volume of the gas left in the apparatus?
.............................................................................................................................. [1]
[Total: 13]
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(a) The table below gives the number of protons, neutrons and electrons in atoms or ions.
Complete the table. The first line is given as an example.
You will need to use the Periodic Table.
particle
number of
protons
number of
electrons
number of
neutrons
A
4
4
5
B
19
18
20
C
30
30
35
D
8
10
8
E
31
31
39
symbol or
formula
9
4 Be
....................
....................
....................
....................
[6]
(b) Using the data in the table, explain how you can determine whether a particle is an atom,
a negative ion or a positive ion.
...........................................................................................................................................
...........................................................................................................................................
..................................................................................................................................... [3]
[Total: 9]
3
The diagram shows some of the processes which determine the percentage of carbon dioxide
in the atmosphere.
carbon dioxide
in atmosphere
combustion
respiration
photosynthesis
(a) Explain how the following two processes alter the percentage of carbon dioxide in the
atmosphere.
(i) combustion
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [3]
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(ii) respiration
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [3]
(b) Photosynthesis reduces the percentage of carbon dioxide in the atmosphere.
(i) Complete the word equation for photosynthesis.
carbon dioxide + water → ........................ + ........................
[2]
(ii) State two essential conditions for the above reaction to occur.
....................................................................................................................................
.............................................................................................................................. [2]
[Total: 10]
4
At present the most important method of manufacturing hydrogen is steam reforming of
methane.
(a) In the first stage of the process, methane reacts with steam at 800 °C.
CH4(g) + H2O(g)
3H2(g) + CO(g)
In the second stage of the process, carbon monoxide reacts with steam at 200 °C.
CO(g) + H2O(g)
CO2(g) + H2(g)
(i) Explain why the position of equilibrium in the first reaction is affected by pressure but
the position of equilibrium in the second reaction is not.
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
(ii) Suggest why a high temperature is needed in the first reaction to get a high yield of
products but in the second reaction a high yield is obtained at a low temperature.
....................................................................................................................................
.............................................................................................................................. [2]
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(b) Two other ways of producing hydrogen are cracking and electrolysis.
(i) Hydrogen can be a product of the cracking of long chain alkanes.
Complete the equation for the cracking of C8H18.
C8H18 → 2............ + H2
[1]
(ii) There are three products of the electrolysis of concentrated aqueous sodium
chloride. Hydrogen is one of them.
Write an equation for the electrode reaction which forms hydrogen.
.............................................................................................................................. [2]
(iii) Name the other two products of the electrolysis of concentrated aqueous sodium
chloride and give a use of each one.
product ............................................
use ............................................
product ............................................
use ............................................
[4]
[Total: 11]
5
Many monomer molecules react together to form one molecule of a polymer. This reaction is
called polymerisation.
(a) The structural formula of the polymer, poly(chloroethene), is given below. This polymer
is also known as PVC.
H
H
C
C
H
Cl n
(i) A major use of PVC is insulation of electric cables. PVC is a poor conductor of
electricity.
Suggest another property which makes it suitable for this use.
.............................................................................................................................. [1]
(ii) One way of disposing of waste PVC is by burning it. This method has the disadvantage
that poisonous gases are formed.
Suggest two poisonous gases which could be formed by the combustion of PVC.
.............................................................................................................................. [2]
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For
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(b) (i) Deduce the structural formula of the monomer from that of the polymer.
H
CH3
C
C
H
H
n
structural formula of monomer
[1]
(ii) Deduce the structural formula of the polymer, poly(phenylethene), from the formula
of its monomer, phenylethene.
H
C 6H 5
C
H
C
H
structural formula of polymer
[2]
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(c) The carbohydrate, glucose, polymerises to form the more complex carbohydrate starch.
If glucose is represented by
HO
OH
then the structural formula of starch is as drawn below.
O
O
How does the polymerisation of glucose differ from that of an alkene such as phenylethene?
...........................................................................................................................................
...........................................................................................................................................
..................................................................................................................................... [2]
[Total: 8]
6
Aluminium is an important metal with a wide range of uses.
(a) Aluminium is obtained by the electrolysis of aluminium oxide dissolved in molten cryolite.
waste gases
oxygen given off
at carbon anode (+)
molten mixture of
aluminium oxide and cryolite
carbon cathode (–)
aluminium
(i) Solid aluminium oxide is a poor conductor of electricity. It conducts either when
molten or when dissolved in molten cryolite. Explain why.
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
(ii) Why is a solution of aluminium oxide in molten cryolite used rather than molten
aluminium oxide?
.............................................................................................................................. [1]
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(iii) Explain why the carbon anodes need to be replaced periodically.
.............................................................................................................................. [1]
(iv) One reason why graphite is used for the electrodes is that it is a good conductor of
electricity. Give another reason.
.............................................................................................................................. [1]
(b) Aluminium is used to make food containers because it resists corrosion.
Explain why it is not attacked by the acids in food.
...........................................................................................................................................
..................................................................................................................................... [2]
(c) Aluminium is used for overhead power (electricity) cables which usually have a steel
core.
aluminium
steel core
(i) Give two properties of aluminium which make it suitable for this use.
....................................................................................................................................
.............................................................................................................................. [2]
(ii) Explain why the cables have a steel core.
....................................................................................................................................
.............................................................................................................................. [1]
[Total: 10]
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7
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The ester linkage showing all the bonds is drawn as
O
C
O
or more simply it can be written as –COO–.
(a) (i) Give the structural formula of the ester ethyl ethanoate.
[1]
(ii) Deduce the name of the ester formed from methanoic acid and butanol.
.............................................................................................................................. [1]
(b) (i) Which group of naturally occurring compounds contains the ester linkage?
.............................................................................................................................. [1]
(ii) Draw the structural formula of the polyester formed from the following monomers.
HOOCC6H4COOH and HOCH2CH2OH
You are advised to use the simpler form of the ester linkage.
[3]
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(c) Esters can be used as solvents in chromatography. The following shows a chromatogram
of plant acids.
For
Examiner’s
Use
solvent front
the cross represents
the centre of the spot
baseline
sample 1
sample 2
An ester was used as the solvent and the chromatogram was sprayed with bromothymol
blue.
(i) Suggest why it was necessary to spray the chromatogram.
....................................................................................................................................
.............................................................................................................................. [2]
(ii) Explain what is meant by the Rf value of a sample.
....................................................................................................................................
.............................................................................................................................. [1]
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(iii) Calculate the Rf values of the two samples and use the data in the table to identify
the plant acids.
plant acid
Rf value
tartaric acid
0.22
citric acid
0.30
oxalic acid
0.36
malic acid
0.46
succinic acid
0.60
sample 1
Rf = ................
It is ..................... acid.
sample 2
Rf = ................
It is ..................... acid.
[2]
[Total: 11]
8
(a) Define the following
(i) the mole
....................................................................................................................................
.............................................................................................................................. [1]
(ii) the Avogadro constant
....................................................................................................................................
.............................................................................................................................. [1]
(b) Which two of the following contain the same number of molecules?
Show how you arrived at your answer.
2.0 g of methane, CH4
8.0 g of oxygen, O2
2.0 g of ozone, O3
8.0 g of sulfur dioxide, SO2
...........................................................................................................................................
...........................................................................................................................................
..................................................................................................................................... [2]
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(c) 4.8 g of calcium is added to 3.6 g of water. The following reaction occurs.
Ca + 2H2O → Ca(OH)2 + H2
(i) the number of moles of Ca = ....................
the number of moles of H2O = ....................
[1]
(ii) Which reagent is in excess? Explain your choice.
....................................................................................................................................
.............................................................................................................................. [2]
(iii) Calculate the mass of the reagent named in (ii) which remained at the end of the
experiment.
....................................................................................................................................
.............................................................................................................................. [1]
[Total: 8]
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BLANK PAGE
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BLANK PAGE
© UCLES 2013
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© UCLES 2013
Magnesium
Sodium
Calcium
0620/32/M/J/13
Strontium
89
Key
b
X
a
72
b = proton (atomic) number
X = atomic symbol
a = relative atomic mass
*58-71 Lanthanoid series
90-103 Actinoid series
88
Ac
Actinium
Ra
Radium
Fr
Francium
87
*
Hafnium
Lanthanum
57
178
Hf
40
Zirconium
Zr
91
Titanium
139
Yttrium
22
48
Ti
La
39
Y
89
Scandium
21
227
56
Barium
Caesium
45
Sc
226
55
137
Ba
133
Cs
38
Rubidium
37
88
Sr
85
Rb
20
Potassium
19
40
Ca
39
12
24
Mg
23
Na
Beryllium
4
Lithium
K
11
3
9
Be
7
II
Li
I
93
Ta
181
Niobium
Nb
90
58
73
52
96
Mo
W
184
Protactinium
Thorium
55
Tc
186
Re
144
Nd
92
60
Uranium
U
238
Neodymium
75
Rhenium
43
Technetium
25
Manganese
Mn
27
59
28
59
29
64
30
65
5
Ru
101
Iron
190
Pm
Osmium
Os
93
Np
Neptunium
61
Promethium
76
44
Ruthenium
26
56
Fe
Sm
150
Iridium
94
Pu
Plutonium
62
152
Eu
95
Am
Americium
63
Europium
78
Platinum
195
Pt
192
46
Palladium
Pd
106
Nickel
Ni
Ir
Samarium
77
45
Rhodium
Rh
103
Cobalt
Co
Gd
157
Gold
Au
197
Silver
96
64
Curium
Cm
Gadolinium
79
47
Ag
108
Copper
Cu
201
Bk
Terbium
Tb
159
Mercury
Hg
97
Berkelium
65
80
48
Cadmium
Cd
112
Zinc
Zn
11
6
Dy
162
Thallium
Tl
204
Indium
98
Cf
Californium
66
Es
Holmium
Ho
165
Lead
Pb
207
Tin
99
Einsteinium
67
82
50
119
Sn
115
32
Germanium
Ge
73
Silicon
In
Gallium
Dysprosium
81
49
31
70
Ga
14
28
Si
Carbon
27
Aluminium
13
12
C
Al
Boron
B
7
14
75
Sb
122
Arsenic
As
Bi
209
Fermium
Fm
Erbium
Er
167
Bismuth
100
68
83
51
Antimony
33
15
Phosphorus
P
31
Nitrogen
N
8
Se
79
Sulfur
S
32
Oxygen
Po
169
Md
Thulium
Tm
101
Mendelevium
69
84
Polonium
52
Tellurium
Te
128
Selenium
34
16
16
O
9
Yb
173
Astatine
At
Iodine
I
127
Bromine
Br
80
Chlorine
No
102
Nobelium
70
Ytterbium
85
53
35
17
Cl
35.5
Fluorine
F
19
Lr
Lutetium
Lu
175
Radon
Rn
Xenon
Xe
131
Krypton
Kr
84
Argon
Ar
40
Neon
103
Lawrencium
71
86
54
36
18
10
Ne
20
Helium
2
0
Hydrogen
VII
4
VI
He
V
1
IV
H
III
The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).
91
Pa
Th
232
Praseodymium
Cerium
59
141
Pr
140
74
Tungsten
42
Molybdenum
24
Chromium
Cr
Ce
Tantalum
41
23
Vanadium
V
51
1
Group
DATA SHEET
The Periodic Table of the Elements
16
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